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Studies the baseline levels of polychlorinated dibenzo-p-dioxins in soil and herbage samples collected in the vivinity of a harzdous waste incinerator in Catalonia, Spain.

Polychlorinated biphenyls (PCBs) are a family of 209 congeners listed as Persistent Organic Pollutants in the Stockholm Convention. Although there has been a lot of focus on those congeners present in the Aroclor or Clophen technical mixtures commercialized in the past (legacy PCBs), other industrial processes such as paint and pigment production can generate other congeners as byproducts (Unintentionally Produced PCBs or UP-PCBs). The present study focuses on the analysis of 72 PCB congeners (including 42 UP-PCBs) in the two major rivers surrounding the city of Barcelona -Llobregat and Besós rivers-, and their levels in two wastewater treatment plants during the production of effluents and reclaimed water. It was observed that WWTP can efficiently remove PCBs from untreated water during sludge production where concentrations are six orders of magnitude higher than in water (in the ng g -1 and pg L -1 ranges, respectively). Although PCB levels in the effluent and reclaimed water replenishing the rivers are not negligible, these do not significantly increase the concentrations already found in the studied rivers, and in most cases PCB concentrations in river water are reduced after merging with the reclaimed water due to dilution effect. The presence of UP-PCB-11 (not present in the Aroclor technical mixtures) in the analyzed water and sludge samples is significant (ranging from 22 to 25 % of the total PCB amount in the Besós river), being often one of the most abundant PCB congeners., Competing Interests: Declaration of competing interest The authors confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome., (Copyright © 2024. Published by Elsevier B.V.)

Since the 1940s, per- and polyfluoroalkyl substances (PFAS) have been widely produced and used in various applications due to their unique properties. Consequently, the principal exposure routes of PFAS have been broadly studied, leading to the conclusion that dietary exposure (more specifically, the consumption of fish and seafood) was one of their main contributors. Thus, developing an analytical method that determines the level of PFAS in fish and seafood has become a relevant subject. In this work, a previous analytical method has been optimized to determine 12 PFAS in fish muscle from salmon, tuna, cod, hake, sardine, anchovy, and sole, as well as in seven different seafood species (i.e., cuttlefish, octopus, squid, shrimp, Norway lobster, prawn, and mussel) by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Subsequently, the PFAS profile of the different species was studied to determine if it was consistent with that previously reviewed in the literature and to know the most relevant contribution of PFAS for each species. Finally, human exposure to PFAS through their consumption was estimated by the daily intake for seven different age/gender groups. PFAS were obtained from 0.014 to 0.818 ng g -1 wet weight in fish samples. Sardines, anchovies, and soles presented the highest PFAS levels. However, cod samples also showed some PFAS traces. Regarding seafood, PFAS levels range from 0.03 to 36.7 ng g -1 dry weight for the studied species. A higher concentration of PFAS has been found in the cephalopods' spleens and the crustaceans' heads. PFOS and PFBS were the predominant compounds in each seafood species, respectively. On the other hand, in the case of mussels, which are the less polluted species of the study, contamination by longer-chained PFAS was also observed. Finally, the total intake of PFAS due to fish and shellfish consumption for the Spanish adult population was estimated at 17.82 ng day -1 . Nevertheless, none of the analyzed samples exceeded the European Food Safety Authority (EFSA) risk value for the supervised PFAS in any age/gender group reviewed., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Polybrominated diphenyl ethers (PBDEs) are persistent organic pollutants that can arrive to water bodies from their use as flame retardants in a wide range of applications, such as electric and electronic devices or textiles. In this study, the photodegradation of PBDEs in water samples when applying UV-LED radiation was studied. Irradiation was applied at three different wavelengths (255 nm, 265 nm and 285 nm) and different exposure times. The best degradation conditions for spiked purified water samples were at 285 nm and 240 min, resulting in degradations between 67% and 86%. The optimized methodology was applied to real water samples from different sources: river, marine, wastewater (effluent and influent of treatment plants) and greywater samples. Real water samples were spiked and exposed to 4 hours of irradiation at 285 nm. Successful photodegradation of PBDEs ranging from 51% to 97% was achieved for all PBDE congeners in the different water samples with the exception of the marine one, in which only a 31% of degradation was achieved.

In 1996-1998, a wide surveillance program was initiated in the vicinity of a new hazardous waste incinerator (HWI) placed in Constantí (Catalonia, Spain), which started its regular operations in 1999. The program was aimed at assessing the environmental impact of the facility on the surrounding environment, as well as to evaluate the potential risks for the population living in the neighborhood. Since then, among other measurements, the concentrations of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) have been periodically determined in soil and herbage samples. This study shows the results, corresponding to the period 2013-2016. Data were compared with those obtained in the baseline survey (1996-1998), as well as with those of the previous survey (2011-2012). The median PCDD/F concentrations in soils were 0.44 and 0.33 ng toxic equivalent (I-TEQ)/kg in 2015 and 2016, respectively, with a significant decrease in relation to the baseline survey, and a non-significant decrease between 2015 and 2016. In turn, PCDD/F levels in vegetation showed some fluctuations over time, being the concentrations of PCDD/Fs in 2013 very similar to those found in 2012 (1.11 and 1.23 ng I-TEQ/kg, respectively). These concentrations notably decreased along the three last campaigns (0.16, 0.23, and 0.17 ng I-TEQ/kg in 2014, 2015, and 2016, respectively). These changes would be more related to a number of environmental factors rather than to a variation of PCDD/F emissions by the HWI. With respect to human health risks, exposure to PCDD/Fs in the area under potential influence of the HWI is not of concern, as the current environmental concentrations of PCDD/Fs do not mean additional carcinogenic or non-carcinogenic risks for the local population.

In May 2016, a fire occurred in one of the largest landfills in Europe (Seseña, Toledo, Spain), where 70,000-90,000tons of tires had been illegally accumulated for >15years. Because of the proximity of population nuclei and the duration of the episode (>20days), we conducted a preliminary human health risk assessment study just after the tire fire. Samples of air and soil were collected in 3 areas surrounding the landfill (El Quiñón, at only 500m, and Seseña Nuevo and Seseña Viejo, both at 4km), as well as in background sites. In addition, samples of crops (barley, wheat, cabbage and lettuce) were also obtained from local farmers. The concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and a number of trace elements (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Sn, Tl, and V) were analyzed in all the samples. The concentrations of all the target pollutants, excepting PAHs, were relatively similar at the different sampling zones, irrespective of the distance to the landfill. In turn, a significant increase of PAHs was noted near the tire landfill, with air levels up to 6-times higher than those found at 4km (134 vs. 19.5-22.7ng/m 3 ). Similarly, PAH concentrations in lettuce were relatively higher than those typically found in monitoring programs of food safety. Because of the increase of airborne PAHs, cancer risks due to exposure to environmental pollutants for the population living at El Quiñón, near the landfill, were between 3- and 5-times higher than those estimated for the inhabitants of Seseña. After this preliminary study, further investigations, focused only on PAHs, but more extensive in terms of number of samples, should be conducted to assure that PAHs have been progressively degraded through time., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Dechlorane Plus (DP) is a flame retardant used as a substitute of Mirex since 1970s, but it was not detected in the environment until 2006. Since then, this compound and its main relatives, Dechlorane 602, 603 and 604, have been mainly studied in environmental matrices for monitoring purposes, but the dietary exposure to them has been hardly investigated so far. In the present study, we determined this family of compounds in fish and vegetable oil samples from Catalonia (Spain), most of them used as health supplements. Determination was carried out by gas chromatography-high resolution mass spectrometry (GC-HRMS), after a clean up in a multilayer silica column and preparative high performance liquid chromatography (HPLC) equipped with a pyrenyl(ethyl) column. Concentrations of Dechlorane compounds were between below the limit of detection and 384.2 pg g(-1). Although there are only few studies about the presence of these pollutants in food or feed, concentrations obtained indicated that these compounds are in the same order in fish and vegetable oil health supplements as the few other food and feed studies., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

The concentrations of PCDD/Fs and 18 PCBs (DL- and NDL-) were analyzed in 16 fish and seafood species widely consumed in Catalonia (Spain). The exposure of these pollutants was subsequently estimated according to various groups of population. The concentrations of PCDD/Fs and PCBs showed an important decrease in relation to the baseline study (2000) and our last survey (2008). Sardine and red mullet were the species showing the highest pollutant concentrations, while canned tuna and cuttlefish presented the lowest levels. Sardine was the main contributor to the exposure of PCDD/Fs and PCBs. In contrast, swordfish was the species with the lowest contribution to the exposure of PCDD/Fs, DL-PCBs, and PCDD/Fs+DL-PCBs, while clam was the minor contributor for NDL-PCBs and total PCBs. For all groups of population, the current intakes of PCDD/Fs and PCBs were lower than the TDI (1-4 pg WHO-TEQ/kg body weight/day), being children the group with the highest exposure. However, this exposure should not mean a health risk for this group of population. The current intake of PCDD/Fs and PCBs through fish and seafood consumption was similar or even lower than most values reported in recent studies all over the world., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

A study was performed to assess exposure of the Spanish population to hexabromocyclododecane (HBCD). Based on consumption data statistics, food items from six food groups, i.e., fish and seafood, meat, animal fat, dairy products, eggs, and vegetable oils, were sampled and analyzed for HBCD followed by per capita intake calculations. The highest levels of HBCD were found in the fish and seafood samples (mean value of 11.6 ng/g lw), followed by meat samples (mean value of 2.68 ng/g lw), eggs (mean value of 1.75 ng/g lw), dairy products (mean value of 0.78 ng/g lw), animal fat (mean value of 0.74 ng/g lw), and vegetable oils (mean value of 0.45 ng/g lw). The daily ingestion rate of HBCD was estimated at 2.58 ng (kg of body weight)(-1) day(-1). HBCD mainly came from fish and seafood (56%), but also dairy products (14%) and meat (12%) contributed.

Fish oils are one of the main sources of ω-3 fatty acids. However, they can present elevated levels of some lipophilic pollutants, such as hexabromocyclododecanes (HBCDs). Since data about HBCDs in fish oil samples are very limited, in this study, 25 samples of fish oil for feed and food have been analyzed. Total HBCDs, as well as, α-, β- and γ-diastereoisomers have been determined. Total HBCDs ranged from 0.09 to 26.8ngg(-1), with higher concentrations in fish oil for feed (average value of 9.69ngg(-1)) than those for food (1.14ngg(-1)). Concentrations of α-HBCD (average value of 4.12ngg(-1) in feed samples and 0.48ngg(-1) in food samples) and γ-HBCD (5.05 and 0.43ngg(-1) respectively) were higher than that of β-HBCD (0.52 and 0.19ngg(-1) respectively) in most of the samples. However, none of them was predominant in the samples. Concentrations of HBCDs were compared to concentrations of other pollutants and correlation between dioxin and dioxin-like PCBs levels and HBCDs levels were observed. Intake of HBCDs was calculated for fish oil with human consumption purposes and it ranged from 0.08 to 5.38ng HBCDsd(-1), which could contribute significantly to HBCDs total intake. Enantiomeric fractions were also determined. No clear enrichment was observed for γ-HBCD, while (-)-α-HBCD enrichment was detected in some samples., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

DEHP was quantified into sewage sludge, thermally dried sludge and compost samples from different areas of Catalonia (North East Spain) using high-resolution gas chromatography (HRGC) coupled to a mass spectrometry (MS). The aim of the work was to determine the evolution of this ubiquitous environmental contaminant along some post-treatment sludge processes, such as composting and thermally drying. DEHP concentration detected in some sludges are above the maximum limit suggested by the EC (100 ppm d.m.) for agricultural use. However, the composting and thermally drying reduce the amount of DEHP in sewage sludge to acceptable level for safe land application. The study was completed with the characterization and long-term observation of DEHP in sewage sludge, composted sludge and thermally dried sludge mixed with two types of soils. In all cases, the percentage of DEHP degraded was higher than 50% after 9 months of incubation.

A recently introduced disk for solid-phase extraction of pollutants from water (C18 Speedisk) has been tested for the analysis of polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF). The complete procedure of analysis has been validated with spiked deionized water. The accuracy, expressed as recovery for the sum of 2,3,7,8-substituted congeners. is 92% and the precision, expressed as the RSD of reproducibility, is 5.8%. The limit of detection (LOD), using 2 l of water, is 4.2 pg/l (0.6 pg ITEQ/l) for the sum of 2,3,7,8-substituted congeners. Actually, the C18 Speedisks have substituted the use of other C18 membrane disks in our laboratory because they allow the fast and efficient analysis of samples with high content of suspended material and reduce the time of elution of free-particulate samples. These disks have been successfully applied to the analysis of water from different sources and with very different physical and chemical characteristics: seawater, rain water, an industrial effluent, a landfill leachate and the inlet and chlorinated and non-chlorinated outlet water from a wastewater treatment plant.

Only a few data are reported about the formation of polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) in forest fires. However, the inventories of sources undertaken by several European and American countries consider natural fires as a possible source of PCDD/F and, in some cases, as one of the most important. In our work we have analysed vegetation and soil samples burned in four forest fires which happened in Catalonia in the summer of 1998. The concentration of dioxin-like compounds (PCDD/F, non-ortho polychlorinated bi-phenyls (PCB) and mono-ortho PCB) has been compared to the concentration present in the corresponding unburned material collected in places near the fires but not affected. The results of this preliminary study show very low concentrations in all the samples, both burned and unburned. Although a change in the profile (proportional increase of tetrachlorinated congeners in PCDD/F) is observed in burned samples compared to unburned ones, the absolute values of concentration decrease in most samples. Therefore, natural fires seem not to be an important source of dioxin-like compounds. These results will be confirmed with air emissions measurements in future studies.

The evolution of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) in sewage sludge-amended soils used in the restoration of degraded lands, like quarries, has been studied. Two experiments were performed: one in the lab, under controlled conditions, and another in a quarry. Two different doses of sewage sludge were applied in both experiments (with two types of application in the quarry experiment) and the evolution of the amended soils were compared with that of the respective control soils (without addition of sewage sludge). The samples were analyzed with a previously validated method by HRGC HRMS after the extraction and the necessary clean-up steps. The results reveal that polluted sewage sludge increases PCDD/F concentration in soils and that these compounds are persistent in the matrix after long periods of time.

The analysis of planar (non-ortho) polychlorinated biphenyls (PCB) by HRGC-ECD or HRGC-HRMS requires a fractionation step to avoid the interferences of the bulk of PCB, usually in much higher concentration than the planar ones. In this paper, a new method, based on the fractionation of PCB on SPE commercial tubes pre-packed with Carbopack B, has been developed. After the extract has been applied on the stationary phase, the bulk of PCD are eluted with 15 ml of hexane (fraction I), mono-ortho PCB with 20 ml of hexane/toluene 99:1 (fraction II) and planar PCB with 20 ml of toluene (fraction III) in a station under vacuum. The method has been validated: accuracy (expressed as recovery in %) is >70% and precision (expressed as % RSD) is <20% considering changes of day, analyst and batch of tubes. The method is linear in the range studied. Other advantages are that the method is simple, rapid and it can be easily automated. The application of this separation to the determination of planar PCB in fly-ash extracts from an intercalibration exercise and to sewage sludge, sediment and soil samples has been successful. In addition, this method removes hydrocarbons from the planar PCB fraction and allows its concentration to very small volumes.